The General Catalogue of Variable Stars (GCVS, 4th edition;
Kholopov et al. 1985a, Kholopov et al. 1985b, Kholopov et al. 1987) is
the primary source of information on variable stars. However, not
unexpectedly in a catalog of such size, there are errors present, such
as misclassified objects (not necessarily the fault of the editors!)
and improper references. The accuracy of the coordinates, while
generally sufficient for the ground-based observations the catalog was
meant to support, are not of sufficient accuracy to support
space-based observations with observatories such as the HST, and many
of the references cited (particularly for the finding charts) are in
journals not easily accessible to some astronomers. We have been
collecting the numerous references associated with a particular class
of variable stars --- the cataclysmic variables (CVs) --- with the
goal of producing an improved catalog and atlas for the cataclysmic
variables. Duerbeck (1987, Sp. Sci. Rev., 45, 1) has provided just
such an improved catalog for novae, but that catalog does not include
the novalike variables or the dwarf novae. We did produce such a
catalog containing all types of CVs (Downes and Shara 1993, PASP, 105,
127; Downes Webbink, and Shara 1997, PASP, 109, 345; hereafter DWS),
and we present here an updated, on-line version of our catalog,
containing additional/revised information on objects in the second
edition, as well as information on objects found (or their reference
uncovered) since DWS; the catalog was frozen on February 1, 2006. The
catalog includes all objects which, to our knowledge, have been
classified as a CV at some point in time; those which are no longer
thought to be CVs are given the type NON-CV (see below).

the name of the object in the General Catalogue of
Variable Stars and subsequent Namelists (67th - 77th).
For those objects without variable star
designations, we list the constellation name only (which were derived
from Roman (1987, PASP, 99, 695)).

Since some constellations contain more than one object without a GCVS
designation, in previous versions we included a number (a strictly
provisional designation) after the constellation name. In this revised
form of the catalog, such ad hoc numbering is no longer required.
However, for ease of comparision with previous versions, we will
retain this type of designation for all objects that had it.

whenever possible, the J2000 coordinates of the objects as
measured in the International Celestial Reference System frame, or
taken from the literature. The right ascension is given to the nearest
0.01s, while the declination is given to the nearest 0.1s; for objects
that are very faint or not visible, the coordinates are given to a
lesser accuracy. For faint novae, the coordinates are taken from
Duerbeck (1987, Sp. Sci. Rev., 45, 1) or from the literature (for
recent novae), and are precessed to the J2000 equinox. For those
objects without available/usable finding charts, coordinates have been
obtained from the literature, and are generally given to a lesser
accuracy than those objects measured in this work.

the type of variability of the object. The table below lists
the various types used in this work, which is based on the
classification scheme used in the GCVS. Those types in upper-case
letters are taken directly from the GCVS, while those in lower-case
letters have been obtained from the literature (which was generally in
agreement with the GCVS, and is presumably more secure); whenever
possible, a type from the literature was used. There are many objects
in the catalog designated NON-CV, which are stars that have been
previously cataloged as CVs, and are included for completeness; the
references for these stars are those papers which refute the CV nature
of the objects. The revised classification is given in the notes for
each object.

the MAXimum and MINimum magnitudes for the objects; the
magnitude systems are listed in the table below. For novae, the
primary sources are Duerbeck (1987, Sp. Sci. Rev., 45, 1) and
Duerbeck (2001, private communication), while for the
non-novae, the catalog of Ritter and Kolb (1998, A&A Supp., 129, 83)
is the prime source. When no other references to brightness were
available, the GCVS values are used.

a code for a reference to the coordinates. Entries listed as ICRS
(International Celestial Reference System) have been measured by the
authors in that reference frame; other codes refer to references from
the literature (click on Display References for this Object at the
bottom of the page for the complete reference). An asterisk (*)
following the reference means that there is a comment regarding the
coordinate measurement (see the notes for the object).

a code for a reference to the proper motion; click on Display
References for this Object at the bottom of the page for the
complete reference. An asterisk (*) following the references means
that there is a comment regarding the proper motion (see the notes
for the object).

a code for a reference to the CV classification; click
on Display References for this Object at the bottom of the page for
the complete reference. An asterisk (*) following the references
means that there is a comment regarding the classification (see the
notes for the object).

a code for the original reference from which our chart is
based; click on Display References for this Object at the bottom of
the page for the complete reference. Note that the identifications
of the CVs are based on the published charts (or in some cases
coordinates only), and have not been independently verified by the
authors. An asterisk (*) following the references means that there
is a comment regarding the identification (see the notes for the object).

a code for a reference to a published spectrum; click on
Display References for this Object at the bottom of page for the
complete reference. A suffix of S indicates a spectrum in quiescence,
while a suffix of X indicates a spectrum in outburst. Whenever available,
the quiescent spectrum was chosen for the catalog over an outburst spectrum.
A colon (:) following the reference indicates that:
(i) the spectrum is only described,
(ii) the spectrum is a glass plate tracing, or
(iii) the reference is unconfirmed (only for a few novae in Duerbeck's atlas)

a code for a reference to the period; click on
Display References for this Object at the bottom of page for the
the complete reference. Note that all periods come from the catalog
of Ritter and Kolb (1998, A&A Supp., 129, 83), or from Ritter (private
communication). An asterisk (:) following the references means the
period is uncertain.

Cataclysmic variables have been observed by space-based observatories
for many years, particularly by X-ray missions. We have searched the
archives of the High Energy Astrophysics Science Archive Research
Center (HEASARC) for observations of CVs from X-ray satellites
(Ariel 5, HEAO-1, HEAO-2, EXOSAT, Ginga, ROSAT, and ASCA) and the EUVE
satellite, and the IUE and HST archives for imaging/spectroscopy of CVs; for
on-going missions, our search contains observations in the archives as
of 2001 June. A "Y" in the field means that data from that satellite
exists; for HST data, the notes for the object indicate if the data is
imaging, spectroscopy, photometry, and/or astrometric.

Finding charts for all objects with chart references (including
objects which we have identified based on positional coincidence) are
included. Most charts are based on the Digitized Sky Survey, and
since those plates vary in both color and limiting magnitude, we note
the emulsion and exposure time for each chart. The field-of-view for
the charts is also indicated (mostly 5' x 5'). The table below provides
information on the emulsions:

First Generation DSS, the emulsion/filter combinations are:
POSSI-E POSS-E RED PLATE,
XV SERC-V Equatorial extension,
S SERC-J Survey
Second Generation DSS, the emulsion/filter combinations are:
UK-F 'Galactic Red' survey (UK Schmidt) IIIaF + RG610 SHORT exposure in
galactic plane
POSSII-F POSS-II Red IIIaF + RG610
POSSII-J POSS-II Blue IIIaJ + GG385
ER 'Equatorial Red' survey (UK Schmidt) IIIaF + RG610
XS 'Second Epoch Southern' survey (UK Schmidt) IIIaF + RG610
Some charts are ground-based CCD images, while others (mostly globular
cluster CVs) are HST images; the filters and exposure times for these
are indicated. North is up and East to the left for all charts unless
explicitly noted (for some HST images). Tick marks are used to
identify the object, while circles are used for those fields where
this is not a definitive identification. Note that for some extremely
crowded fields, a circle has been used to mark the object.

We thank all the astronomers, both professional and amateur, who
provided information to support this catalog. We thank Sarah
Stevens-Rayburn and Brenda Corbin for their excellent assistance in
obtaining some of the more obscure references needed to generate the
finding charts, and Mike Potter, Debra Wallace, and Matt McMaster for
assistance in measuring the coordinates and generating the finding
charts. We also thank Anne Gonnella, Steve Hulbert, Calvin Tullos,
and Mike Wiggs for the work in creating the web site, and Karen
Levay for setting up the archival site. R.F.W.
acknowledges the support from NSF grants AST 9618462 and AST 0406726.